code: def check_path(path):
      if not os.path.exists(path):
          readme_file = os.path.normpath(
              os.path.join(os.path.dirname(path), "..", "README.md")
          )
          raise RuntimeError(
              "File '%s' does not exist. Please follow the instructions at %s to download and prepare it."
              % (path, readme_file)
          )
  
file_path: CNTK/Examples/Image/Classification/MLP/Python/SimpleMNIST.py
imports: import argparse
  import numpy
  import sys
  import os
  import cntk
  from cntk.train import Trainer, minibatch_size_schedule
  from cntk.io import MinibatchSource, CTFDeserializer, StreamDef, StreamDefs, INFINITELY_REPEAT
  from cntk.device import cpu, try_set_default_device
  from cntk.learners import adadelta, learning_parameter_schedule_per_sample
  from cntk.ops import relu, element_times, constant
  from cntk.layers import Dense, Sequential, For
  from cntk.losses import cross_entropy_with_softmax
  from cntk.metrics import classification_error
  from cntk.train.training_session import *
  from cntk.logging import ProgressPrinter, TensorBoardProgressWriter
label_desc: Use image node_id 1 for calling a global function with example usage: check_path(path) without return types